A multi-proxy study of the Cerro Piche Graben - A Lower Jurassic basin in the central North Patagonian Massif, Argentina

The volcano-sedimentary succession of the Cerro Piche Graben, Río Negro province, Patagonia (Argentina), was studied U–Pb and Lu–Hf in zircon. As well, a stratigraphic, sedimentological, palynology review paleoflora content made. combined stratigraphic geochronological study on indicates that Graben developed during Early Jurassic allow us to propose Formation. This formation is composed lower volcanic (named Loma Blanca Member) restricted tectonic depression probably emplaced Sinemurian (ca. 191 Ma), an upper sedimentary El Tono unconformably deposited over sequence Pliensbachian 183 Ma). sedimentological allows recognition nine cycles related evolution alluvial fan. palynofacies interpretations reflect intermittent exposure weathering and/or intense reworking organic components as result dynamic system with high terrestrial input, sediment reworking, subaerial exposure. preserved this exclusively conifers assigned Cupessinoxylon sp., corresponds arboreal paleocommunity. data detrital zircon grains from Member indicate maximum depositional age (MDA) 185 Ma for sequence, support reworked continental crust source. . Additionally, obtained work together North Patagonian Massif supports four magmatic cycles, called C0, C1 (including C1i source), C2 C3. (172–180 Ma) C3 (155–162 mixing juvenile mantle-derived crustal parental magma zircons C0 (182–192 cycle, which includes distal volcanism identified (166–169 seemingly represent three episodes reworking.